Explosively actuated tool



Nov. 21, 1961 R. c. KVAVLE EXPLOSIVELY ACTUATED TOOL Filed Feb. 28, 1957 @Q Q R Van INVENTOR. ROBERT C. KVAVLE BY BUCKHORN, CHEATHAM & BLORE A TTOPNEYJ' United States Patent 3,009,157 EXPLOSIVELY ACTUATED TOOL Robert C. Kvavle, Newberg, Oreg., assignor to Omark Industries, Inc., Portland, Oreg., a corporation of Oregon Filed Oct. 28, 1957, Ser. No. 692,758 2 Claims. (Cl. 1-106) This invention relates to an explosively actuated tool and more particularly to a tool in which the barrel may be rapidly and easily removed and replaced and in which a cartridge removing member for removing a cartridge from a breech plug is positioned closely adjacent the rear end of the barrel for ease in removing spent cartridges from the tool. a

It is frequently necessary or desirable to interchange the barrels of explosively actuated tools both to. enable barrels having different size internal bores to be employed and to replace worn or damaged barrels. In tools employing a barrel block enclosing the rear end of the barrel of the tool in conjunction with a breech block movable relative to the barrel block for exposing the rear end of such barrel block the barrel has ordinarily been screwthreaded into the barrel block. Such screwthreads are adjacent the portion of the tool where the explosive forces are generated by firing a blank cartridge and the heat and' corrosive gases produced frequently render the barrels ditficult to remove from the barrel block after a period of use and, in any event, unscrewing the barrel from the barrel block and screwing another barrel into position is time consuming. Also, tools adapted for readily interchangeable barrels present a cartridge extraction problem as it'is difiicult to provide an effective extractor mech position in the barrel block. The barrel has an enlarged.

rear end interfitting with a portion of the barrel block to hold the barrel against rotation and to prevent it from being moved completely through the barrel block. The barrel is held in position in the barrel block by a holding means between the front end of the barrel blockand the muzzle end of the barrel. Also, a cartridge removing member is carried on the rear portion ofthe barrel block so as to be exposed when the tool is opened by moving the breech block relative to the barrel block. Such cartridge removing member is conveniently placed for the removal of a spent carriage from a breech plug removably carried in the breech end of the barrel. A spent cartridge may be rapidly removed from the tool by removing the breech plug from the barrel and placing it upon the cartridge removing member and when desired, different barrels may be substituted for each other in a rapid and expeditious manner.

It is therefore an object of the present invention to provide an improved powder actuated tool in which provision is made for easily and rapidly removing a barrel from its operative position in a barrel block and substituting another barrel.

Another object of the invention is to provide an explosively actuated tool in which a barrel is held in operative position in a barrel block and may be removed therefrom by rearward sliding of the barrel through the barrel block after releasing a holding means between the front end of the barrel block and the muzzle end of the barrel.

Another object of the invention is to provide an explosively actuated tool in which a barrel block not only provides for ease of interchanging barrels held in operative position in the barrel block but also provides an improved extraction structure for removing a spent carof the barrel block and the breech end of the barrel held therein and in which a cartridge removing member is carried by the rear end of the barrel block so as to beexposed when the breech block is moved to expose the rear end of the barrel block.

Other objects and advantages of the invention will appear in the following description of a preferred embodiment given in connection with the attached drawings, of which:

' FIG. 1 is a plan view of the tool of the present invention shown in open position and with a portion broken away to show the pivotal connection between the barrel portion and handle portion of the tool;

FIG. 2 is a longitudinal vertical section on an enlarged scale through the center line of the tool of FIG. 1 with the tool shown in closed position and loaded for use;

FIG. 3 is a horizontal fragmentary section through the barrel block and the breech end of the barrel of the tool of the present invention looking in the direction of the arrows 33 of FIG. 2 but showing the breech plug removed from the barrel and in position on the cartridge removing member;

FIG. 4 is an elevation of the tear or breech end of the barrel block looking in the direction of the arrows 4-4 of FIG. 2 but with the barrel and breech plug removed; and.

FIG. 5 is a rear end elevationof the barrel of FIG. 3. Referring more particularly to the drawings, as shown in FIG. 1,.the tool of the present invention includes a front or barrel portion 10 and rear or handle portion 12 pivoted to each other about a pivot pin 14 which pivotally connects a breech block 16 forming part of the handle portion of the tool and a barrel block 18 forming a part of the barrel portion 10 of the tool. The barrel block 18 is flattened, as shown in FIG. 4, so as to have greater width than heighth and the breech block 16, shown in FIGS. 1 and 2, isin the form of a yoke having upper V and lower arms 20 and 22, respectively, (FIG. 2) extending forwardly and fitting the upper and lower surfaces of the barrel block 18.

i The barrel block 18 has a centrally disposed longitudinally extending internal bore 24 therein for receiving the rear end of a barrel 26. The rear portion of the barrel block 18 is cut away to provide a vertically extending wall 28 adjacent but slightly spaced from the wall of the bore 24, the wall 28 also extending parallel to the axis of the bore 24. The barrel 26 has an enlarged rear end portion 30 having fiat sides 32, one of which engages the wall 28 to prevent rotation of the barrel in the barrel block 18. The enlarged rear end 30 of the barrel holds the barrel in position with respect to the barrel block but enables the barrel to he slid rearwardly out of the barrel block. It will be noted in FIG. 3 that the pivot pin 14 has a cut away portion at 34 to provide clearance for the barrel 26 and that such pivot pin 14 is held in adjusted position by a set screw 36 screw-threaded into the barrel block 18.

The front or muzzle end of the barrel 26 extends'forwardly of the barrel block 18 through a barrel housing sleeve 38 forming the forward portion of a barrel housing 40 also including a barrel block sleeve 42 forming the rear portion of the barrel housing 40. The barrel block sleeve 42 has its forward end surrounding the rear Patented Nov. 21, 1961.

are secured together in any desired manner, for example, by brazing and the barrel housing sleeve 38 has a rubber cover 48. The barrel 26 has its muzzle end exteriorly screw-threaded and a barrel sleeve 50, which has its muzzle end interiorly screw-threaded, is threaded upon the muzzle end of the barrel. The rear end' of the barrel sleeve 50 terminates intermediate the length of the barrel in an enlarged portion 53 providing a shoulder against which the forward end of a barrel housing spring 52 engages. The spring 52 is a compression coil spring and the rear end of the barrel housing sleeve 38 has an inwardly directed flange 54 against which the rear end of the spring 52 engages. It will be apparent that the spring 52 urges the barrel sleeve 50 and barrel 26 to which it is attached forwardly with respect to the barrel housing sleeve 38. Since the barrel has its enlarged rear end portion positioned in the rear portion of the barrel block 18, such block is also urged forwardly against the rear end of the barrel housing sleeve 38. The barrel is thus urged forwardly in the barrel block 18 and is retained' in position in the barrel block by the spring 52.

A safety shield 56 is held on the muzzle end of the barrel 26 by means of a nut 58 also screw-threaded on the muzzle end of the barrel and such safety shield has a safety shield sleeve 60 extending rearwardly into the barrel housing sleeve 38 so as to surround the spring 52 and the barrel sleeve 50. A second compression spring 62 urges the safety shield 56 forward against the nut 58. It will be apparent that the safety shield 56 may be removed from the tool by unscrewing the nut 58. The safety shield sleeve 60 can then be slid forwardly of the tool to remove such safety shield from the tool and the spring 62 can also be removed by pulling it forwardly from the interior of the barrel housing sleeve 38. When the sleeve 60 is removed from the interior of the barrel housing sleeve 38, a spring pressed latch 64 carried by the barrel housing sleeve 38 engages an annular notch on the enlarged rear end 53 of' the barrel sleeve 50 to prevent rearward movement of the barrel unless the safety shield 56 is in place. Upon reinsertion of the safety shield sleeve 60 into the barrel housing sleeve 38, the spring pressed latch 64 is cammed out of engagement with the barrel sleeve 50. The purpose of the latch 64 is to prevent accidental discharge of the tool when the safety shield 56 is removed, since as explained below, the tool cannot be fired' unless the housing portions of the tool have been moved forwardly with respect to the barrel 26 and associated parts, for example, by engagement of the nut 58 on the muzzle of the barrel with a work surface while an operator pushes on the handle portion 12 of the tool. The particular tool illustrated, also has a spring pressed detent 66 carried by the barrel housing sleeve 38 and which engages behind the rear end of the safety shield sleeve 60 to hold the sleeve in a forward position for use with a barrel extension as known in the art. Depression of the rear end of the detent 66 enables the safety shield sleeve 60 to be reinserted in the barrel housing sleeve 38 to the position shown in FIG. 2.

It will be apparent that the barrel 26 may be removed from the tool when the tool is in the open position shown in FIG. 1. This is accomplished by first removing the nut 58 (FIG. 2) from the end of the barrel and removing the safety shield 56 and safety shield spring 62 as above described. The barrel sleeve 50 may then be removed by unscrewing it from the muzzle end of the barrel 26 and for this purpose the muzzle end of such sleeve has notches 68 therein for engagement with a suitable tool. As soon as the barrel sleeve 50 has been removed, the barrel housing spring 52 can be removed and the barrel 26 can be pushed rearwardly out of the barrel block 18 and a new barrel substituted therefor. That is to say, the new barrel can be inserted through the rear end of the barrel block 18 and moved by a longitudinal sliding motion into the position shown in FIGS. 2 and 3 and the spring 52 and barrel sleeve 50 can then be re- 4 installed after which the spring 62 and safety shield 56 can be reinstalled.

As shown in FIGS. 2 and 3, the rear end of the barrel 26 has an enlarged counter bore 70 for receiving the cylindrical body of a breech plug 72 having an enlarged head 73. The breech plug 72 contains a chamber 74 for the reception of a cartridge 76. The breech plug 72 has a sliding fit in the counter bore 70 so that it may be readily withdrawn and reinserted with the fingers. When the tool is in the open position shown in FIG. 1, it is apparent that the breech plug 72 may be readily grasped by the fingers and withdrawn from the barrel 26. When the tool is in the open position and the breech plug 72 is removed from the barrel, a stud 77, shown in FIG. 2, may be loaded into the bore in the barrel from the rear end thereof and moved to a desired position in such bore after which the breech plug 72 is installed in the barrel. A blank cartridge 76 containing a powder charge is then inserted in the chamber in the breech plug and the tool closed for firing. Firing of the tool is accomplished by impact of a firing pin 78 against the rim of the head of the cartridge 76 by mechanism described below. After firing of the tool, the tool may be again opened to the position of FIG. 1. The breech plug carrying the spent cartridge can then be removed from the barrel 26.

The barrel block 18 is provided with a cartridge removing member 80, shown in FIGS. 1, 3 and 4, in the form of a pin or stud having its front end secured in a portion of the barrel block 18 adjacent the barrel 26. The member 80 has its body portion extending rearwardly of the barrel block. The barrel block has a portion cut away adjacent one side of the rear end of the barrel 26 to provide room for the cartridge removing member, so that suchcartridge removing member may extend parallel to the axis of the barrel 26 adjacent the rear end of the barrel. The cartridge removing member 80 is spaced sufficiently laterally from the barrel 26 that the breech plug 72 may be placed thereover so that the member 80 enters the chamber in the breech plug to force a spent cartridge 76 from the breech plug. The cartridge removing member 80 is also displaced sufiiciently laterally from the barrel 26 that the stud 77, shown in FIG. 2, may be inserted into the bore of the barrel without interference with the head 73 of the breech plug 72 when the breech plug is in position on the cartridge removing member 80. The breech plug may then again be replaced in the bore 70 of the barrel and a new cartridge 76 inserted in its chamber. The tool may then again be closed for firing.

The preferred form of firing mechanism is disclosed in more detail in my copending application Serial No. 692,711, filed October 28, 1957, now Patent No. 2,923,940, granted February 9, 1960, and preferably includes the safety mechanism shown in such application, which safety mechanism prevents accidental firing of the tool when the tool is subjected to an impact. Such safety mechanism is not shown in the present application and only so much of the firing mechanism as is necessary for an understanding of the general operation of the tool is shown herein. Such firing mechanism includes a firing pin 78 which has its front end received in an internal bore in a tubular member 81 forming part of and extending rearwardly from the breech block 16. The rear end of the firing pin 78 is received in a bore 82 in a rubber covered handle member 84 and is urged forwardly of said handle member by means of a compression spring 86 between the bottom of the bore 82 and a collar 88 intermediate the length of the firing pin 78. The handle member 84 is secured by means of the screw 90 to the rear of a ring member 92 secured in the rear end of an action housing sleeve 94 which in conjunction with the handle member 84 and ring member 92 provides an action housing for the breech block 22' and firing mechanism of the gun. The action housing is held in position on the breech block 16 by means of a spring pressed plunger 96 which is positioned in a laterally extending bore in the breech block and has its outer end extending into a longitudinally extending slot 98 in the sleeve 94. The slot 98 is preferably covered by a small cover plate having an aperture 100 in alignment with the plunger 96 when the parts are in the position shown in FIG. 2. By employing a punch or other small instrument, the plunger 96 can be depressed by inserting the instrument through the aperture 100 after which the entire action housing and parts carried thereby including the firing pin 78 can be removed from the remainder of the tool including breech block 16 when the tool is in closed condition. The cartridge removing member 80 is completely enclosed by the action housing sleeve 94' and the tool cannot be closed when the breech plug 72 is on the member 80. I

When the tool is assembled as shown in FIG. 2 and is in closed position, the housing portions of the tool including the handle member 84, the action housing sleeve 94 and the barrel housing 40 can be moved against the force of the spring 52 forwardly of the tool with respect to the barrel and associated parts including the barrel block 18 and the breech block 16 to which the barrel block is pivoted. The firing pin 78 has a shoulder adjacent its forward end which engages a scar 102 pivotally mounted upon the rear end of the breech block 16 to hold the firing pin stationary, the sear having a portion extending into a slot in the tubular member 81 into engagement with the firing pin and being spring pressed toward the firing pin. Forward movement of the handle member 84 with respect to the breech block and seat 102 carried thereby compresses the firing pin spring 86. At the same time a sear engaging portion 106 of a trigger 108 is moved to a position above a trigger engaging portion 104 of the sear 102, the trigger 108 being pivotally mounted on the handle member 84 and urged to a non actuated position shown in FIG. 2 by a spring 110. Upon pressing the safety shield 56 and the nut 58 on the muzzle end of the barrel against a work surface by pressure exerted upon the handle member 84, the housing portions of the tool, including the action housing sleeve 94 and handle member 84, are moved forwardly to compress the firing pin spring 86. This positions the trigger 108, to actuate the sear to release such sear from the firing pin 78 so as to enable the firing pin to be driven forwardly by the spring 86 to fire the cartridge 76.

The operation of the entire tool should be apparent from the above description. After the tool has been fired as just described, it is opened to the position shown in FIG. 1. The breech plug 72 carrying a spent cartridge is then removed from its position in the rear end of the barrel 26 and placed upon the cartridge removing member 80 which is carried by the barrel block adjacent the breech end of the barrel and which is exposed when the tool is opened. Placing the breech plug upon the member 80 forces the cartridge 76 from the breech plug 72. A stud 77 to be driven by the tool is then inserted in the bore of the barrel 26 and moved to a desired position along the barrel, such as the position shown in FIG. 2. The, breech plug 72 is then reinserted into the rear end of the barrel 26 and a fresh cartridge inserted into the breech plug. The tool is then brought to the closed posit-ion by pivoting the handle portion 12 into alignment with the barrel portion The breech block 16 closes the rear end of the breech plug 72 in the barrel 26 and the tool is ready for use. The tool is held in the closed position by a latch mechanism not described in the present application but described and claimed in the copending application of Wilber I. Cranston, Serial No. 701,635, rfiled December 9, 1957, now Patent No. 2,913,728, granted November 24, 1959.

The muzzle end of the tool is pressed against a work surface by pressure exerted on the handle member 84 and this causes the housing portions of the tool including the handle member 84, the action housing sleeve 94 and barrel housing sleeve 38 to move forwardly against the force of the spring 52. Forward movement of the han- 6 dle member with respect to the barrel block 18 and also the breech block 16 and the sear 102 carried by the breech block 16 compresses the firing pin spring 86 and at the same time positions the sear engaging portion 106 of the trigger above the trigger engaging portion 104 of the sear 102. Actuation of the trigger moves the sear 102 out of engagement with the firing pin 78 to allow the spring 86 to drive the firing pin against the rim of the head of the cartridge 76 to fire the tool. The tool may then again be reopened, as soon as it is removed from contact with the work surface to enable the spent cartridge to be removed and the tool to be again loaded.

If at any time it is desirable to change the barrel 26, either to substitute a barrel with a different size bore for driving different size studs or to replace a worn barrel, the tool is first brought to the open position shown. in FIG. 1, the nut 58 is then unscrewed from the barrel which releases the safety shield 56 allowing such shield and the safety shield sleeve 60 as well as the safety shieldspring 6-2 to be withdrawn from the muzzle end of the gun. The barrel sleeve 50 is then unscrewed from the muzzle end of the barrel and this enables the barrel 26 to be pushed rearwardly out of the barrel block 18. Another barrel can then be inserted through the rear end of the barrel block 18 and positioned so that a flat side 32 of the enlarged rear end of the barrel is in contact with the wall 28. The barrel sleeve 50 can then be threaded onto the new barrel to compress the spring 52 and the safety shield 56 reinstalled. Depression of the detent 66 allows the safety shield sleeve 60 to be inserted to the position shown in FIG. 2, after which the nut 58 can be threaded upon the end of the barrel and the tool is again in operative condition.

While I have disclosed the preferred embodiment of the invention, it is understood that the details thereof may be varied and that the scope of the invention is to be determined by the following claims.

I claim:

1. An explosively actuated too-l comprising a housing including a handle portion and a barrel portion, an axially elongated barrel block positioned within said housing and having a forward end and a breech end, said barrel block having an axially extending aperture therethrough, a barrel extending through and slidably fitting said aperture andhaving a muzzle end and an enlarged breech end constituting means preventing passage of the breech end of said barrel forwardly through said aperture, an annular abutment means fixed Within said housing and positioned forwardly of said barrel block and surrounding said barrel, screw-threaded means threaded on said barrel and positioned forwardly of said abutment means, compression spring means surrounding said barrel and extending between said screw-threaded means and said abutment means for urging said barrel forwardly to urge said barrel block against said abutment and hold said barrel in said barrel block, a breech block positioned in said housing, means pivoting said breech block to said barrel block for movement of said breech block relative to said barrel block from a closed tool position adjacent the breech end of said barrel to an open tool position spaced from the breech end of said barrel, said spring means acting through said abutment means and said screw-threaded means constituting the sole means for holding said barrel against sliding motion rearwardly in said barrel block when said breech block is in said open tool position.

2. An explosively actuated tool comprising a housing including a handle portion and a barrel portion, an axially elongated barrel block positioned within said housing and having a forward end and a breech end, said barrel block having an axially extending aperture therethrough, a barrel extending through and slidably fitting said aperture and having a muzzle end and an enlarged breech end constituting means preventing passage of the breech end of said barrel forwardly through said aperture, an annular abutment means fixed within said housing and positioned forwardly of said barrel block and surrounding said barrel, screw-threaded means threaded on said barrel and positioned forwardly of said abutment means, compression spring means surrounding said barrel and extending between said screw-threaded means and said abutment means for urging said barrel forwardly to urge said barrel block against said abutment and hold said barrel in said barrel block, a breech block positioned in said housing, means pivoting said breech block to said barrel block for movement of said breech block relative to said barrel block from a closed tool position adjacent the breech end of said barrel to an open tool position spaced from the breech end of the said barrel, means mounting said housing on said barrel block and said breech block for sliding movement forwardly of said tool against the force of said spring means when said tool is in said tool closed position and the muzzle end of said barrel is pressed against a workpiece by pressure applied through said handle portion, said spring means acting 8 through said abutmentmeans and said screw-threaded means to return said housing rearwardly on said barrel block and said breech block and constituting the sole means for holding said barrel against sliding motion rearwardly of said barrel block when said breech block is in said open tool position.

References Cited in the file of this patent UNITED STATES PATENTS 

